In Long Term Evolution (LTE) Release 10, a base station configures a CSI-RS for a User Equipment (UE). Correspondingly, the base station may transmit the CSI-RS within a specific subframe, and the UE may perform channel quality measurement on the basis of the CSI-RS, e.g., measuring a Precoding Matrix Indicator (PMI), a Channel Quality Indicator (CQI) or a Rank Indicator (RI), or performing a rate matching operation.
In a Time Division Duplexing (TDD) system, one radio frame includes a normal uplink subframe, a normal downlink subframe and a special subframe (which is a downlink subframe). All of the normal subframes and the special subframe may be used to transmit the CSI-RS, but different physical resources may be occupied by the CSI-RS within the subframes of different types. Hence, in the case of determining a position of a CSI-RS resource, the UE needs to determine whether or not a subframe within which the CSI-RS is to be transmitted is the special subframe or the normal downlink subframe, and then determine the position of the CSI-RS resource. Usually, a type of the subframe, e.g., the normal downlink subframe or the special subframe, may be determined in accordance with an uplink/downlink subframe configuration. A current LTE system supports various uplink/downlink subframe configurations, and in some cases, it may further support a dynamic change in the uplink/downlink subframe configurations.
Hence, there is an urgent need to determine the position of the CSI-RS resource in accordance with the uplink/downlink subframe configuration.